In relation to musical drums, regardless of the type of drum, the heads must be properly tensioned (or tuned) prior to playing. Traditional drum head tensioning systems (FIG. 13) involve a system of threaded tension rods 42 and brackets 40. The brackets 40, with interior female threading, are bolted into the exterior of the shell of the drum 10. The tension rods 44, with exterior male threading 42, are inserted through holes in a tensioning hoop 50 that is secured over the rim of the drum head 20. The tension rods 44 are then individually screwed into the brackets 40 on the shell 10. When the drum is tuned, each tension rod 44 is individually tightened, and the drum head tuned overall by means of hitting the drum head 20 with a drum stick or tapping on the drum head near each tension rod 44 individually and gradually bringing the entire drum head up to the desired tension and its associated tone.
Since tightening of any single tension rod affects overall tension, this process must be repeated a number of times to bring the head to final tension. If the drum has a head on each end, this entire process is repeated for both heads. This approach has several downsides: attachment of the brackets to the drum shell requires penetrating the shell with a large number of holes, which may adversely affect sound, and which adds significantly to the cost of manufacture. More importantly, the drum cannot readily be tuned during performance, since the tap-and-tighten approach to tuning is time consuming and requires a reasonably quiet environment to be able to hear the tone at each individual tension rod. When a drum head is struck near the rim or tension rod, the volume is much lower than hitting the drum in the center of the drum head. Hitting the drum head in the center to check the overall tuning is only useful after all tension rods are adjusted equally. In the case of the bottom head, it would also require removing the drum from its stand and flipping it over to repeat the process. Neither the requisite time or the quiet environment are likely to be available in a live music venue, making tuning or re-tuning during a performance effectively impossible. These issues are also generally present in other musical instruments with a similar membrane-shell architecture.
Prior attempts to develop a cable tensioned drum tuning apparatus are impractical or flawed for several reasons:
They involve very complex mechanisms with a great number of moving parts which are sensitive to mis-adjustment, and therefore impractical for the needs of performing percussionists (see U.S. Pat. No. 9,349,355 FIG. 2).
They require drums that are purpose-built to take the specific tuning mechanism in question, and are therefore useless to the percussionist using a standard drum kit (see U.S. Pat. No. 7,488,882).
They require bulky components or separate hand tools (see U.S. Pat. No. 795,034).
They involve a pulley housing apparatus which is fixed parallel to the top-bottom axis of the drum shell and does not allow the pulley to follow the angle at which the cable is traversing the circumference of the drum shell (FIG. 10 prior art—pulley lies fixed parallel to the drum shell, resulting in the cable winding across the pulley at a skewed angle), and (FIG. 1 showing the path of cable traversing the circumference of the drum, and illustrating that in traversing the circumference of the drum, the cable cannot leave a parallel pulley on an axis perpendicular to the pulley axis when the pulley is parallel to the drum shell.) In this last case, the skewed angle at which the cable passes through the pulley induces uneven stresses on both the pulley assembly and cable. Any cable tensioning system that uses pulley assemblies that do not account for this phenomenon creates higher friction resulting in uneven cable tension and therefore uneven drum head tension throughout the circumference of the drum, resulting in poor tuning. Further, the exit of the cable from the pulley at an angle that is not perpendicular to the axis of the pulley exerts uneven force on the pulley, its shaft and its housing. Drum heads are tuned to very high tensions, and this uneven force inevitably leads to uneven wear of the pulley axle shaft, deformation of the pulley assembly and the housing, and to premature failure of the entire pulley assembly. This is a particularly undesirable trait in drums. They are used very roughly and very often, and in circumstances where major repairs are not possible, so durability and reliability are highly prized qualities.